When trying to import shared definitions from a XML Schema, I can properly reference shared types, but referencing shared elements causes validation errors.

This is the schema that imports the shared definitions (example.xsd):

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema
  elementFormDefault="qualified"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  xmlns:shared="http://shared.com">

    <xs:import namespace="http://shared.com" schemaLocation="shared.xsd"/>

    <xs:element name="example">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="importedElement"/>
                <xs:element ref="importedType"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="importedElement">
        <xs:complexType>
            <xs:sequence>
                <xs:element ref="shared:fooElement"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:element name="importedType">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="bar" type="shared:barType"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

</xs:schema>

These are the shared definitions (shared.xsd):

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns="http://shared.com"
    targetNamespace="http://shared.com">

    <xs:element name="fooElement">
        <xs:simpleType>
            <xs:restriction base="xs:integer"/>
        </xs:simpleType>
    </xs:element>

    <xs:simpleType name="barType">
        <xs:restriction base="xs:integer"/>
    </xs:simpleType>

</xs:schema>

Now consider this XML instance:

<?xml version="1.0"?>
<example
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"                     
  xsi:noNamespaceSchemaLocation="example.xsd">
    <importedElement>
        <fooElement>42</fooElement>
    </importedElement>
    <importedType>
        <bar>42</bar>
    </importedType>
</example>

When validated, the "importedType" works perfectly fine, but the "importedElement" gives the following error:

Invalid content was found starting with element 'fooElement'. One of '{"http://shared.com":fooElement}' is expected

I would guess that my troubles are related to namespace issues (hence the somehow misleading "got fooElement but was expecting fooElement") -- any hints on what's wrong here?